Electrostatic printers are known in which a toner image is fused or fixed to a substrate to form a final document. The fusing can occur after transfer of the toner image to the substrate, or transfer and fusing simultaneously occur in a transfuse process. In either arrangement the substrate is fed into a fusing nip where a combination of fusing members, such as fusing or transfuse belts or rollers, apply heat and pressure to the toner image and substrate to fix or fuse the toner image to the substrate. During the fusing process, toner particles from the toner image and debris from the substrate can adhere to the fusing member. These toner particles and other debris, contaminants, can transfer from the fusing member to subsequent documents resulting in print defects. In addition, build up of toner particles on the fusing member can degrade the quality of fusing of the toner image on subsequent documents. The build up of toner particles can also decrease the operational life of the fusing member.
Therefore it is preferred to clean the fusing members to remove toner particles and other particulate debris, such as dirt and fiber, that effect final print quality.
One prior cleaner employed a cleaning roller engaging the surface of a fuser roll to remove toner particles. Toner particles preferentially adhered to the cleaner roller. However, as excess toner particles accumulate on the cleaner roller, the toner layer on the surface of the cleaner roller can become uneven, resulting in uneven cleaning of the fusing member. The toner layer on the cleaner roller can become excessively thick, requiring maintenance to remove the excess toner of the toner layer.
In one alternative assembly, the cleaner roller is formed of a hollow cylinder and apertures are provided in the cylinder to permit excess toner to be driven inward through the openings. Excess toner therefore is collected on the inside of the cylinder, extending the period between servicing or the life of the cleaner roller. However, the openings can result in gaps in the cleaning surface of the roller, requiring multiple cycles to the fusing member to completely clean the surface of the fusing member by the cleaner roller. Therefore toner particles on the fusing member can continue to disrupt fusing, or be transferred to subsequent documents, before their removal.